I did see the welcome message from PureFTPd though...
Ok. Then your problem is not related to the problem in this thread. This thread is about pure-ftpd not starting at all and not about authentication problems.
I've seen in your other thread that you installed a wrong FTP server before instead of following the perfect server guide. This is most likely the resaon for the authentication problems, as there are soem config changes nescessary for pure-ftpd and it is required that pure-ftpd is installed before ispconfig gets installed or the pure-fdtpd logins will fail.
To fiy our setup, please redo the steps to install pure-ftpd that are diescribed in the perfect setup guide, especially the change sin the inetd file are nescessary to ensure that pure-ftpd runs in standalone mode. When you verifies and changed these settings, run a manual ispconfig update and select to recionfigure services.